Answer:
Moving from left to right across a period, the atomic radius decreases. The nucleus of the atom gains protons moving from left to right, increasing the positive charge of the nucleus and increasing the attractive force of the nucleus upon the electrons.
Answer:the atomic radius will decrease.The nucleus of the atom will gain protons moving from left to right
Explanation:
11 The cross section compares the densities of different Earth layers. Which Earth layer is most dense?
Answer:
b
Explanation:
i took the quiz
Mary is standing on a train moving east at 10 km per hour. Alicia is sitting on a train that passes in the opposite direction at 30 km per hour. From Mary's point of view, how fast is Alicia moving?
Help
Which describes the titration graph when a strong acid is titrated by a weak base?
It begins at a low pH and has an equivalence point of 7.
It begins at a low pH and has an equivalence point less than 7.
It begins at a high pH and has an equivalence point of 7.
It begins at a high pH and has an equivalence point greater than 7.
Answer:
the answer is b edg 2021
Explanation:
it just is
May someone assist, please...? I don't know how to do chemistry work...
1) How many mL of 5.00M CaSO4 solution must be
diluted with water to prepare 500.0 mL of 0.900M CaSO4?
2) 20.0 mL of a stock solution of NaOH is diluted with water to prepare 150.0mL of 1.50 M NaOH solution.
Calculate the Molarity of the stock NaOH solution?
3) 12.00 mL of 3.50 M NaOH solution is diluted with 88.0 mL of water.
What is the concentration of sodium hydroxide in the diluted solution?
4) 9.0 mL of 8.0 M HCl solution is diluted with water to prepare 0.50 M HCl solution. What is the final volume of this solution?
Answer:
1) 90.0 mL
2) 11.25 M
3) 0.477 M
4) 144 mL
Explanation:
The main formula that will be used for all these calculations is:
C₁V₁ = C₂V₂
C stands for concentration and V stands for volume and the subscripts 1 and 2 indicate an initial concentration or volume and a final concentration or volume.
For each problem, it's best to start by figuring out what you have and what you need to find. Figure out if you're looking for an initial value or a final value.
1) We need to find the initial volume. So, take what values you have and plug them in and then solve for whatever variable:
5.00 M · V₁ = 500.0mL · 0.900 M - divide by 5.00
C₁ = 90.0 mL
2) This time we're finding the initial concentration:
20.0mL · C₁ = 150.0mL · 1.50 M - divide by 20.0mL
C₂ = 11.25 M
3) Now we're finding the final concentration:
12.00mL · 3.50 M = 88.0mL · C₂ - divide by 88.0mL
C₂ = 0.477 M
4) Finally, we're looking for the final volume:
9.0mL · 8.0 M = 0.50 M · V₂ - divide by 0.50 M
V₂ = 144mL
PLZZ HELP!!!!!!! What is PH
What is the pH of an HCl solution if [H+] = 0.03?
A. 0.03
B. 1.5
C. 3.0
D. 3.5
Answer: B
Explanation:
1.5 :D
Question 1
A molecule contains carbon, hydrogen and oxygen. For every carbon atom there are
twice as many hydrogen atoms but the same number of oxygen atoms.
What is the formula of the molecule?
А
CH 0
B
C2H4O2
C
C,H,O2
D
C,H,O2
The required molecule is :
=》option B.) C2H4O2
it has 2 carbon atoms, 4 hydrogen atoms which it twice the number of carbon atoms and 2 oxygen atoms same as carbon.
How much 2 M HBr is needed to neutralize 380 mL of 0.1 M NH4OH?
Answer:
19ml
Explanation:
trust me
Given the equation:
Zn + 2HCl → ZnCl2 + H2
How many moles of HCl would be required to
produce a total of 2 moles of H2?
Answer:
4 moles of HCl will be required to produce 2 moles of H2.
Explanation:
A balanced chemical equation gives the stoichiometric ration of moles of reactants required to produce a certain number of moles of products. The ratio of moles of reactants to moles of products is known as the mole ratio and is constant for a given chemical reaction.
In the given balanced equation of reaction shown below:
Zn + 2HCl → ZnCl2 + H2
The mole ratio of HCl and H2 is 2:1. This means that in this reaction between Zinc metal and hydrochoric acid to produc zinc chloride and hydrogen gas, every two moles of hydrochloric acid used in the reaction will result in the production of one mole of hydrogen gas.
Therefore for two moles of H2 to be obtained from the reaction, twice the number of moles of HCl is required.
Moles of HCl required = 2 × 2 moles = 4 moles of HCl.
Can y’all help with question 17
Answer:
7. Option 2. Atom 1 and Atom 4
8. The same number of valence electron
Explanation:
7. Determination of which symbol represent an isotope.
Isotopes are atoms having the same atomic number but different mass number due to the difference in the neutron number.
From the question given above, the following were obtained:
Z => atomic number
A => mass number
Atom >>> Isotope >>>>> Z >>>> A
1 >>>>>>> ¹⁷₇E >>>>>>>> 7 >>>> 17
2 >>>>>>> ¹⁷₈E >>>>>>> 8 >>>> 17
3 >>>>>>> ¹⁸₆E >>>>>>> 6 >>>> 18
4 >>>>>>> ¹⁸₇E >>>>>>> 7 >>>> 18
From the table above, only atom 1 and 4 has the same atomic number. Hence, atom 1 and atom 4 are isotopes.
8. To know the correct answer to the question, we shall write the electronic configuration of magnesium and calcium. This can be obtained as follow:
Mg (12) => 1s² 2s²2p⁶ 3s²
Valence electron => 2
Ca (20) => 1s² 2s²2p⁶ 3s²3p⁶ 4s²
Valence electron => 2
We can see that magnesium and calcium both have the same valence electron. Hence, they will have similar chemical properties.
list a few reasons why the oxygen level decreases in case
Answer:
Blood oxygen level is the amount of oxygen circulating in the blood. Most of the oxygen is carried by red blood cells, which collect oxygen from the lungs and deliver it to all parts of the body.Blood oxygen level is the amount of oxygen circulating in the blood. Most of the oxygen is carried by red blood cells, which collect oxygen from the lungs and deliver it to all parts of the body.The body closely monitors blood oxygen levels to keep them within a specific range, so that there is enough oxygen for the needs of every cell in the body.Blood oxygen level is the amount of oxygen circulating in the blood. Most of the oxygen is carried by red blood cells, which collect oxygen from the lungs and deliver it to all parts of the body.The body closely monitors blood oxygen levels to keep them within a specific range, so that there is enough oxygen for the needs of every cell in the body.A person’s blood oxygen level is an indicator of how well the body distributes oxygen from the lungs to the cells, and it can be important for people’s healthExplanation:
"Oxygen fuels our living processes. It contracts our muscles, helps our cells to work, grow and regenerate, feeds our brains, calms our nerves, helps the heart to pump, cleanses the body of toxins, fights infection and boosts immunity," says Dr Jena, Director, Institute of Emergency Medicine, Mission Hospital & Research Center , Madurai.
Lungs:
Once air enters the nose or mouth, it gets humidified and reaches the oliveoli, tiny air sacs that help to pull in oxygen and transfer it into the blood stream and also to pull out the carbon dioxide and push it out of the lungs and back up to breathe out. destroys these oliveoli by thickening the walls so gas exchange becomes difficult.
Heart :
The left side of your heart receives oxygen-rich blood from your lungs and pumps it through your arteries to the rest of your body. The right side of your heart receives oxygen-poor blood from your veins and pumps it to your lungs, where it gets rid of the carbon dioxide and picks up oxygen. Inan increase in oxygen demand occurs because of compromised lungs and fear (that excites the body). This may lead to heart damage, especially if the arteries were already clogged.
this may help you hope so
What is the molecular formula for this molecule? a
Answer:
In a molecular formula, it states the total number of atoms of each element in a molecule.
Explanation:
I need help with this question!!
Answer:
Fossil fuels..........
help me get this right
Answer:I’m 100% it’s the second one
Explanation:
I have done it before and missed one but not this question
2 C5H5 + Fe = Fe(C5H5)2
What is reproduction?
What is the percentage by mass of copper in copper oxide (CuO)?
Answer:
79.89%
Explanation:
Copper has a molar mass of 63.55
Oxygen has a molar mass of 16.00
If you add these you get 79.55
To get the mass percent of copper divide copper by the whole. 63.55/79.55*100= 79.89%
How many moles of carbon is 1.88 x 1025 carbon atoms?
Answer:
31.23 molesExplanation:
To find the number of moles in a substance given it's number of entities we use the formula
[tex]n = \frac{N}{L} \\[/tex]
where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
we have
[tex]n = \frac{1.88 \times {10}^{25} }{6.02 \times {10}^{23} } \\ = 31.229235...[/tex]
We have the final answer as
31.23 molesHope this helps you
Which of the following effect increases the solubility of Ca(OH)2?
O Adding an acidic solution
O Adding KOH
O Adding solid CaCl,
O Adding solid NaOH
O Adding CaCO3
Answer:
adding an acidic solution
Explanation:
Strong acids dissociate completely in water and the H⁺ ions react with the OH⁻ ions to make H₂O. If we add an acid to our solution of Ca(OH)₂, the acid protons would react with some of the OH⁻ ions and drive the equilibrium to the right. More of the solid Ca(OH)₂ should dissolve.
Will give brainliest please help!!
Answer:
D. The energy level of the electron.
Explanation:
There are four quantum numbers which are used to describe the movement and paths or positon of each electron within an atom. Quantum numbers can be used to determine the electronic configuration of atoms and the most likely location of the atom's electrons. Quantum numbers are also used in determining other characteristics of atoms, such as ionization energy and the atomic radius.
The four quantum numbers are namely, principal, azimuthal, magnetic and spin quantum numbers.
Principal quantum numbers are denoted by the symbol ‘n’. They describe the principal electron shell or energy level the atom.The value of the principal quantum number are positive integer values that is equal to or greater than one. The value n = 1 represents the innermost electron shell of an atom, which corresponds to the lowest energy state of an electron. The larger the values of 'n' the greater the energy level and the farther the electron is from the nucleus.
Li + H2O + LiOH + H2
How do I balance this?
Answer:
2Li + 2H2O → 2LiOH + H2
Explanation:
Lithium + Water = Lithium Hydroxide + Dihydrogen
What is the standard cell notation of a galvanic cell made with zinc and gold?
A. Zn2+(aq) | Zn(s) || Au(s) | Au+(aq)
B. Au(s)| Aut(aq) || Zn2+(aq) | Zn(s)
C. Aut (aq)| Au(s) || Zn(s) | Zn2+(aq)
D. Zn(s) | Zn2+ (aq) || Aut(aq) | Au(s)
Answer:
D
Explanation:
use of sodium trioxocabonates iv
Answer:
Sodium hydrogen trioxocarbonate(IV) is also known as baking soda, and has the molecular formula NaHCO3. Industrial Preparation of NaHCO3. The salt is manufactured industrially by the solvay process by saturating a wet mush of Na2CO3 obtained from the solvay process with CO2. Na2CO3(aq) + H2O(l) + CO2(g) → 2NaHCO3(s)
Explanation:
Hope it helps
FOLLOW MY ACCOUNT PLS PLS
This tool is used to measure
Answer:
C. volume
Explanation:
who discovered electron
Answer: Electricity
Answer:
J.J Thomas in 1897
1. Which is true for any element?
A. Atomic number = number of protons + number of electrons
B. Atomic number = nun number of protons
C. Atomic number = number of protons + number of neutrons
D. Atomic number = nun number of protons, electrons, and neutrons
Please help it’s my final
Which model shows a way that large molecules can enter a cell without using the cell's energy? Outside the cell O A Cell membrane Vacuole 1 2 Inside the cell В.
Answer:
its B
Explanation:
I took the test and its that passage way thing. (tell me if this works for you! it will but just wanna make sure!)
help me get it right and no links
Answer:
limited
Explanation:
have a good day :)
What is the source of solar energy? electricity . solar panels the sun None of the above
Answer:
The Sun
Explanation:
Solar power is energy from the sun that is converted into thermal or electrical energy.
Answer:
The sun
Explanation:
The sun is the main source of solar energy.
1. How many grams of NaOH are needed to react with two moles of H2SO4? 2NaOH + H2SO4 Na2SO4 + 2H20
Explanation:
Explanation:
Given the molecular weights:
M
r
N
a
O
H
=
40
g
m
o
l
M
r
N
a
2
S
O
4
=
142
g
m
o
l
The analogy of the moles will be held constant:
n
N
a
O
H
n
N
a
2
S
O
4
=
2
1
n
N
a
O
H
n
N
a
2
S
O
4
=
2
For each one, substitute:
n
=
m
M
r
Therefore:
n
N
a
O
H
n
N
a
2
S
O
4
=
2
m
N
a
O
H
M
r
N
a
O
H
m
N
a
2
S
O
4
M
r
N
a
2
S
O
4
=
2
200
40
x
142
=
2
200
⋅
142
40
x
=
2
200
⋅
142
=
2
⋅
40
x
x
=
200
⋅
142
2
⋅
40
=
100
⋅
142
40
=
10
⋅
142
4
=
1420
4
=
=
710
2
=
355
g
r
a
m
s
(or just use a calculator